Control method of a rear oxygen sensor, vehicle, and product

Abstract

The embodiment of the application is suitable for the technical field of vehicles, and provides a control method of a rear oxygen sensor, a vehicle and a product. The method comprises the following steps: in a current driving cycle, obtaining engine start-stop information when a hybrid vehicle is driving; determining an engine start-stop working condition based on the start-stop information; when the start-stop working condition is a frequent start-stop working condition, switching a heating voltage control strategy of the rear oxygen sensor from a first strategy to a second strategy; the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same working scenario; and adjusting the heating voltage of the rear oxygen sensor based on the second strategy. By using the above method, the failure rate of the rear oxygen sensor can be reduced when the engine is frequently started and stopped.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicles, and particularly relates to a control method of a rear oxygen sensor, a vehicle and a product. BACKGROUND

[0002] In order to meet the automobile emission regulations, the rear oxygen sensor becomes a standard configuration of a hybrid vehicle and is used for monitoring the oxygen concentration in exhaust gas. However, in an actual scenario, if the engine is frequently started and stopped during the driving of the hybrid vehicle, the exhaust gas with insufficient combustion will continuously pollute the rear oxygen sensor, so that the rear oxygen sensor cannot work normally.

[0003] At present, in the prior art, a fault prompt is usually performed after the rear oxygen sensor is polluted until a fault occurs, so as to remind the vehicle owner to replace the rear oxygen sensor, and there is no control strategy for the polluted rear oxygen sensor. Therefore, the failure rate of the rear oxygen sensor is high. SUMMARY

[0004] The embodiments of the application provide a control method of a rear oxygen sensor, a vehicle and a product, and can solve the problem that the prior art has no good control strategy for controlling the rear oxygen sensor, so as to reduce the high failure rate of the rear oxygen sensor.

[0005] In a first aspect, the embodiments of the application provide a control method of a rear oxygen sensor, which comprises the following steps.

[0006] In a current driving cycle, engine start-stop information during the driving of the hybrid vehicle is acquired;

[0007] An engine start-stop working condition is determined based on the start-stop information;

[0008] When the start-stop working condition is a frequent start-stop working condition, a heating voltage control strategy of the rear oxygen sensor is switched from a first strategy to a second strategy; the heating voltage of the rear oxygen sensor determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same working scenario;

[0009] The heating voltage of the rear oxygen sensor is adjusted based on the second strategy.

[0010] In an embodiment, the start-stop information comprises a start-stop frequency; the acquisition of the engine start-stop information during the driving of the hybrid vehicle comprises the following steps.

[0011] When the engine is switched from a starting state to a stopping state, exhaust gas information at the rear oxygen sensor is acquired;

[0012] The start-stop frequency is determined based on the exhaust gas information.

[0013] In an embodiment, the determination of the start-stop frequency based on the exhaust gas information comprises the following steps.

[0014] determine the fuel combustion condition of the engine based on the exhaust information;

[0015] if the fuel combustion condition is fuel fully combustion, maintain the start-stop number unchanged;

[0016] if the fuel combustion condition is fuel not fully combustion, add the current start-stop number and a preset value to obtain an updated start-stop number.

[0017] In an embodiment, the exhaust information at least includes one of exhaust temperature and content of combustion byproducts; determining the fuel combustion condition of the engine based on the exhaust information includes:

[0018] if the exhaust temperature is less than or equal to a preset temperature, and / or, the content of combustion byproducts is greater than a preset content, determining the fuel combustion condition as fuel not fully combustion;

[0019] if the exhaust temperature is greater than the preset temperature, and the content of combustion byproducts is less than or equal to the preset content, determining the fuel combustion condition as fuel fully combustion.

[0020] In an embodiment, the start-stop information includes a start-stop number; determining the start-stop condition of the engine based on the start-stop information includes:

[0021] if the start-stop number is greater than a preset number, determining the start-stop condition as frequent start-stop condition;

[0022] if the start-stop number is less than or equal to the preset number, determining the start-stop condition as normal start-stop condition.

[0023] In an embodiment, the start-stop information includes an interval duration between each start and stop of the engine; determining the start-stop condition of the engine based on the start-stop information further includes:

[0024] determining an average duration of the multiple interval durations;

[0025] if the average duration is less than or equal to a preset duration, determining the start-stop condition as frequent start-stop condition;

[0026] if the average duration is greater than the preset duration, determining the start-stop condition as normal start-stop condition.

[0027] In an embodiment, the method further includes:

[0028] at a beginning stage of each driving cycle, determining the heating voltage based on the first strategy, and performing the target step and steps after the target step; the target step includes obtaining start-stop information of the engine when the hybrid vehicle is driving.

[0029] In an embodiment, the first strategy and the second strategy are respectively used to describe a corresponding relationship between exhaust gas temperature at the rear oxygen sensor and heating voltage; wherein, at the same exhaust gas temperature, a voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature.

[0030] In a second aspect, the embodiments of the present application provide a control device of a rear oxygen sensor, the device comprising:

[0031] The acquisition module is configured to acquire start-stop information of the engine when the hybrid vehicle is running in a current driving cycle.

[0032] The determination module is configured to determine a start-stop working condition of the engine based on the start-stop information.

[0033] The switching module is configured to switch a heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy when the start-stop working condition is a frequent start-stop working condition; the rear oxygen sensor determines, under the same working scenario, a heating voltage from the second strategy to be greater than or equal to a heating voltage from the first strategy.

[0034] The adjusting module is configured to adjust the heating voltage of the rear oxygen sensor based on the second strategy.

[0035] In a third aspect, the embodiments of the present application provide a vehicle, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method of the first aspect when executing the computer program.

[0036] In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method of the first aspect.

[0037] In a fifth aspect, the embodiments of the present application provide a computer program product, when the computer program product is executed on a vehicle, the vehicle executes the method of the first aspect.

[0038] The beneficial effects of this application embodiment compared to the prior art are as follows: In the current driving cycle, the start-stop information of the engine during hybrid vehicle operation can be obtained to determine the engine's start-stop condition based on the start-stop information. When the start-stop condition is a frequent start-stop condition, it can be considered that frequent engine start-stop may lead to incomplete combustion of fuel, causing the oil residue generated by incomplete combustion to adhere to the rear oxygen sensor, thus contaminating the rear oxygen sensor. Based on this, in order to protect the rear oxygen sensor, when the start-stop condition is a frequent start-stop condition, the heating voltage control strategy of the rear oxygen sensor can be switched from the first strategy to the second strategy. Since, under the same conditions, the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy, when adjusting the heating voltage of the rear oxygen sensor based on the second strategy, the temperature of the rear oxygen sensor operating based on the heating voltage will be greater than or equal to the temperature operating based on the heating voltage determined by the first strategy. Furthermore, the rear oxygen sensor can decompose and volatilize the exhaust oil residue adhering to its surface based on a higher heating temperature, stabilizing the performance of the internal sensor elements, enabling the rear oxygen sensor to recover its function at high temperatures, and reducing the failure rate of the rear oxygen sensor. Furthermore, determining the heating voltage based on the second strategy allows for a more reasonable determination compared to a subjectively set heating voltage. This, in turn, maximizes energy savings while ensuring the oxygen sensor can recover its function at high temperatures. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart illustrating the implementation of a control method for a post-oxygen sensor according to an embodiment of this application;

[0041] Figure 2 This is a flowchart illustrating the implementation of a control method for a post-oxygen sensor according to another embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the structure of a control device for a post-oxygen sensor provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application. Detailed Implementation

[0044] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, technologies, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

[0045] It should be understood that the term "comprises" when used in this specification and the appended claims, specifies the presence of stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0046] It should be noted that the information collection process (such as the face image collection process, the fingerprint information collection process, etc.) / feature extraction process involved in the present application is executed with the user's knowledge and permission, i.e., the information collection process / feature extraction process meets the legal and regulatory requirements and does not belong to the act of obstructing public interests.

[0047] In addition, in the description of the specification and the appended claims, the terms "first", "second", "third", etc. are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0048] In order to meet the automobile emission regulations, the rear oxygen sensor becomes a standard configuration of hybrid vehicles, which is used to monitor the oxygen concentration in the exhaust gas. However, in actual scenarios, if the engine is frequently started and stopped during the driving of the hybrid vehicle, the exhaust gas with insufficient combustion will continuously pollute the rear oxygen sensor, causing the rear oxygen sensor to fail to work normally.

[0049] For example, there are some active substances on the surface of the ceramic sensitive element in the rear oxygen sensor, which participate in the sensing of oxygen concentration. When polluted by the exhaust gas with insufficient combustion, the activity of the active substances will be inhibited, reducing the ability to chemically react with oxygen molecules in the exhaust gas, thereby affecting the accurate detection of the change in oxygen concentration by the rear oxygen sensor.

[0050] Currently, in the prior art, fault prompts are usually given after the rear oxygen sensor is polluted until it fails, to remind the vehicle owner to replace it, and there is no control strategy for the rear oxygen sensor after it is polluted.

[0051] Based on this, in order to be able to protect the rear oxygen sensor and reduce the failure rate of the rear oxygen sensor under the frequent start-stop working condition of the engine, an embodiment of the present application provides a control method of a rear oxygen sensor, which can be applied to a hybrid vehicle. For example, the present application does not make any limitation on the specific type of electronic equipment such as the vehicle controller, central controller, etc. on the hybrid vehicle.

[0052] Please refer to Figure 1 , Figure 1 An implementation flowchart of a control method of a rear oxygen sensor provided by an embodiment of the present application is shown, which includes the following steps:

[0053] S101, in the current driving cycle, the start-stop information of the engine when the hybrid vehicle is running is obtained.

[0054] In an embodiment, the driving cycle generally refers to a complete process of the hybrid vehicle from starting to experiencing a series of running states (such as acceleration, deceleration, uniform speed driving, etc.) until finally parking and turning off. A driving cycle can be considered as a complete use stage of the hybrid vehicle.

[0055] Therefore, the current driving cycle can be considered as a driving cycle that the hybrid vehicle is currently performing, which is different from the driving cycle that has been ended before or the driving cycle that will occur in the future.

[0056] In an embodiment, the hybrid vehicle is a hybrid vehicle, which combines the advantages of traditional fuel engines and electric drive systems, has two power sources of fuel engines and electric motors, and the two can work cooperatively according to different working conditions. For example, the electric motor can be relied on for driving when the hybrid vehicle starts and drives at low speed, achieving zero emission and low noise; when driving at high speed and needing large power output, the fuel engine can be involved or both can work together.

[0057] It can be understood that, since the hybrid vehicle has two power sources, the engine can be frequently started and stopped in a driving cycle.

[0058] In an embodiment, the start-stop information includes but is not limited to the number of starts and stops of the engine, the interval time between each start and stop, the temperature and speed of the engine, etc., which is not limited.

[0059] It should be noted that, since it is necessary to determine whether the start-stop working condition of the engine is a frequent start-stop working condition based on the start-stop information, at least one of the number of starts and stops and the interval time can be used as the start-stop information for ease of explanation.

[0060] In the embodiment, the engine start-up can be determined when the engine speed starts to increase from 0 or a start-up instruction of the engine is received. The engine stop can be determined when the engine speed decreases to 0 or a stop instruction of the engine is received. The method of determining the engine start-up and stop is not limited in the embodiment.

[0061] In an embodiment, the hybrid vehicle can count the total number of times that the engine starts from the idle state and then stops in the current driving cycle, and determine the total number as the start-stop number. One start-stop number is composed of one start-up and one stop. Or, one stop of the engine is considered to be accompanied by one start-up of the engine. Therefore, the start-stop number can also be considered as the stop number of the engine. The method of counting the start-stop number is not limited in the embodiment.

[0062] For example, in a driving cycle of a city traffic jam, the hybrid vehicle is usually prone to encounter scenes such as hybrid vehicle congestion and waiting for a traffic light. Therefore, the engine can start and stop frequently. At this time, the start-stop number is usually relatively large. For a driving cycle of smooth driving on a highway, the engine can start and run for a long time. At this time, the start-stop number is usually relatively small.

[0063] In addition, the hybrid vehicle can take the length of time between each engine stop and the next start-up, or the length of time between each engine start-up and stop (i.e., the running time after the engine starts) as the interval length. In the embodiment, the length of time between each engine start-up and stop can be taken as the interval length.

[0064] For example, taking the hybrid vehicle encountering a red light in the city and the engine stopping as an example, the engine starts again when the green light is on. At this time, after the engine starts and the hybrid vehicle drives to the intersection, if the intersection is a red light, the difference between the time of engine start-up and the time of the hybrid vehicle driving to the intersection can be considered as the interval length.

[0065] Based on the above description, it can be considered that the start-stop number and the interval length can reflect whether the engine starts and stops frequently to a certain extent.

[0066] S102, determining the start-stop working condition of the engine based on the start-stop information.

[0067] In an embodiment, the start-stop working condition includes a frequent start-stop working condition and a normal start-stop working condition. It can be understood that when the engine is in the frequent start-stop working condition, the engine runs for a short time after each start-up, so that the fuel is not sufficient to produce a large amount of oil stains when the engine runs. At this time, a large amount of oil stains will seriously pollute the downstream oxygen sensor.

[0068] In addition, when the engine is in the normal start-stop working condition, it can be considered that the engine runs for a long time after each start, so that the fuel is fully combusted when the engine runs without or with a small amount of oil pollution. Furthermore, the rear oxygen sensor is not polluted in the normal start-stop working condition.

[0069] Based on the above description, it can be considered that the frequent start-stop working condition is a start-stop working condition that is easy to pollute the rear oxygen sensor with a large amount of oil pollution. In addition, the normal start-stop working condition is a start-stop working condition that does not pollute the rear oxygen sensor.

[0070] Based on the above explanation of the start-stop information, as an example, the hybrid vehicle can determine the average length of the multiple interval lengths. Then, when the average length is less than or equal to the preset length, it is determined that the start-stop working condition is the frequent start-stop working condition. Otherwise, when the average length is greater than the preset length, it is determined that the start-stop working condition is the normal start-stop working condition.

[0071] In an embodiment, the above-mentioned preset length can be set according to actual conditions, which is not limited. For example, the above-mentioned preset length can be 3 minutes.

[0072] It can be understood that after each start of the engine, if it is stopped running within a short time, it can be considered that due to the short running time of the engine, the temperature in the engine is low, which will not effectively make the fuel fully combusted. Furthermore, the engine will produce a large amount of oil pollution to the rear oxygen sensor from each start to stop. Based on this, when the average length is less than or equal to the preset length, it can be determined that the start-stop working condition is the frequent start-stop working condition that is easy to pollute the rear oxygen sensor with oil pollution.

[0073] Specifically, after the engine starts, it usually takes a certain length of time for the temperature of the engine to reach the normal working temperature. At this time, when the engine temperature is low, the fuel injected into the cylinder cannot be well mixed with the air. In addition, when the engine starts, the control system of the engine usually injects a relatively large amount of fuel in order to make the engine reach the normal working temperature as soon as possible. Therefore, this will also increase the possibility of incomplete combustion of fuel. Based on this, it can be considered that when the interval length is small (for example, less than or equal to the preset length), the fuel cannot be fully combusted.

[0074] In addition, based on the above description, when the average length is less than or equal to the preset length, it can be considered that the running time of the engine after each start is short. Furthermore, in the case of multiple incomplete combustion of fuel, it will further increase the degree of pollution of the rear oxygen sensor.

[0075] Therefore, by judging the start-stop working condition according to the comparison between the average time length and the preset time length, the pollution degree of the rear oxygen sensor caused by the start-stop information of the engine can be determined more objectively and accurately. Furthermore, a reliable basis can be provided for the adjustment of the heating voltage control strategy of the rear oxygen sensor, and the accuracy of the adjustment of the heating voltage control strategy can be improved.

[0076] In another embodiment, the hybrid vehicle can also determine that the start-stop working condition is the frequent start-stop working condition when the start-stop number is greater than the preset number. Otherwise, when the start-stop number is less than or equal to the preset number, it is determined that the start-stop working condition is the normal start-stop working condition.

[0077] In an embodiment, the preset number can be set according to actual conditions, which is not limited. For example, the preset number can be 7.

[0078] It can be understood that when the start-stop number is greater than the preset number, it can be considered that the possibility of insufficient fuel of the engine will increase. Furthermore, in the case of increasing possibility of insufficient fuel, the possibility of pollution of the rear oxygen sensor will also increase until the pollution degree is aggravated and the rear oxygen sensor fails.

[0079] Therefore, it can be considered that the start-stop number can accurately reflect whether the hybrid vehicle is in the frequent start-stop working condition that is easy to cause a large amount of oil pollution to pollute the rear oxygen sensor, and can also provide a reliable basis for the adjustment of the heating voltage control strategy of the rear oxygen sensor, and the accuracy of the adjustment of the heating voltage control strategy can be improved.

[0080] In another embodiment, the hybrid vehicle can also determine that the start-stop working condition is the frequent start-stop working condition when the start-stop number is greater than the preset number and / or the average time length is less than or equal to the preset time length. That is, when any start-stop information meets the corresponding determination condition, it is determined that the engine is in the frequent start-stop working condition. Otherwise, when the start-stop number is less than or equal to the preset number and the average time length is greater than the preset time length, it is determined that the start-stop working condition is the normal start-stop working condition.

[0081] Therefore, compared with the disadvantage that only relying on a single start-stop information may not accurately reflect the real start-stop working condition, the start-stop working condition can be determined by combining the start-stop number and the average time length, which can realize comprehensive consideration of the start-stop working condition from different angles, and the judgment of the actual start-stop working condition of the engine is more comprehensive and accurate.

[0082] It needs to be particularly pointed out that each time the engine starts and stops, only the possibility of engine fuel insufficiency can be determined, and the possibility of the engine fuel insufficiency cannot be accurately determined. Further, the determination of the hybrid vehicle in the frequent start-stop condition of the rear oxygen sensor which is easy to produce a large amount of oil pollution based on the start-stop number determined only based on the start and stop of the engine may have certain misrecognition.

[0083] Based on this, in order to accurately determine the start-stop number of the engine, the hybrid vehicle can also obtain the exhaust information at the rear oxygen sensor when the engine is switched from the start state to the stop state, so as to determine the start-stop number based on the exhaust information.

[0084] In an embodiment, the above-mentioned exhaust information at least includes one of the exhaust temperature and the content of the combustion by-products, which is not limited.

[0085] It needs to be pointed out that when the engine fuel is fully combusted, the exhaust temperature is usually greater than the preset temperature. The preset temperature can be set according to the actual situation, which is not limited.

[0086] For example, when the hybrid vehicle is in a high-speed driving or climbing driving condition, the engine will be operated at high load. At this time, the hybrid vehicle needs more fuel combustion to provide power. Therefore, under the above driving condition, the heat generated when the fuel is fully combusted will increase significantly, and the exhaust temperature will rise accordingly.

[0087] In addition, when the hybrid vehicle is in an idle or low-load running condition, the engine will be operated at low load. At this time, the hybrid vehicle does not need a large amount of fuel combustion to provide power. Further, under the above driving condition, the exhaust temperature when the fuel is fully combusted will also rise, but the rising amplitude is relatively low.

[0088] Based on this, the above-mentioned preset temperature can be set to have multiple, and each preset temperature can correspond to one driving condition of the hybrid vehicle, so that the judgment of the fuel combustion condition based on the preset temperature is more accurate and practical.

[0089] In addition, the above-mentioned combustion by-products include but are not limited to carbon monoxide and hydrocarbons, etc., which are not limited. It can be understood that when the engine fuel is not fully combusted, the content of the above-mentioned combustion by-products will increase significantly.

[0090] Based on this, the hybrid vehicle can determine that the fuel combustion condition is fuel insufficiency when the content of the combustion by-products is greater than the preset content. Otherwise, when the content of the combustion by-products is less than or equal to the preset content, it is determined that the fuel combustion condition is fuel fully combusted.

[0091] The preset content can be set according to actual conditions, and the preset content corresponding to different combustion byproducts can be different, and this is not limited.

[0092] It can be understood that, in the case of ideal fuel full combustion, the fuel (mainly hydrocarbons) in the engine fully reacts with oxygen. Taking gasoline as an example, the main component of gasoline is a variety of hydrocarbons, such as octane. When the fuel and sufficient air (about 21% of air is oxygen) are mixed in the cylinder of the engine, after the spark plug is ignited, the carbon element combines with oxygen to form carbon dioxide, and the hydrogen element combines with oxygen to form water. These two substances are the main products of fuel combustion and are produced in large quantities in the normal combustion process.

[0093] And when the fuel is not fully combusted, carbon monoxide and hydrocarbons are produced because the mixing ratio of fuel and air is improper, or the oxygen supply is insufficient during combustion, causing incomplete combustion of the fuel, producing carbon monoxide. And in the case of incomplete combustion of fuel, or the part that does not participate in combustion, will appear in the form of hydrocarbons in the exhaust gas.

[0094] Based on the above description, the hybrid vehicle can determine the fuel combustion condition of the engine based on the exhaust gas information. Then, when the fuel combustion condition is full combustion of fuel, it can be considered that even if the engine has undergone a start-stop process, since the fuel is fully combusted, it will not cause pollution to the rear oxygen sensor. Based on this, the hybrid vehicle can maintain the number of start-stops unchanged.

[0095] Otherwise, when the fuel combustion condition is that the fuel is not fully combusted, it can be considered that the start-stop process of the engine this time may pollute the rear oxygen sensor. That is, the possibility of pollution of the rear oxygen sensor increases. Further, the current start-stop number can be added to the preset value to obtain an updated start-stop number, so that the updated start-stop number is closer to the preset number corresponding to the frequent start-stop working condition of the engine.

[0096] For example, taking the preset value as 1 and the preset number in the above example as 7 times as an example, if the current start-stop number is 3 times, it can be considered that the engine start-stop this time will not pollute the rear oxygen sensor when it is determined that the fuel combustion condition is full combustion of fuel. Therefore, the start-stop number of 3 times can be maintained unchanged.

[0097] Otherwise, when it is determined that the fuel combustion condition is that the fuel is not fully combusted, it can be considered that the start-stop process of the engine this time will pollute the rear oxygen sensor. Therefore, the current start-stop number 3 can be added to the preset value 1 to obtain an updated start-stop number 4. It can be understood that, compared with the current start-stop number 3, the updated start-stop number 4 is closer to the preset number 7 corresponding to the frequent start-stop working condition of the engine.

[0098] Based on the above example of tail gas information and fuel combustion, as a specific example, the hybrid vehicle can consider that the fuel combustion is not sufficient when the tail gas temperature is less than or equal to a preset temperature and / or the content of combustion by-products is greater than a preset content. Otherwise, when the tail gas temperature is greater than the preset temperature and the content of combustion by-products is less than or equal to the preset content, the fuel combustion is determined to be sufficient.

[0099] It should be noted that, by combining the tail gas temperature and the content of combustion by-products to determine the fuel combustion, comprehensive consideration of the fuel combustion from different angles can be achieved. Specifically, the tail gas temperature can indirectly reflect whether the fuel is sufficiently combusted, while the content of combustion by-products directly reflects whether the fuel is completely converted into the expected product and whether there are excess combustion by-products. Further, by combining the tail gas temperature and the content of combustion by-products for comprehensive analysis, the fuel combustion can be more accurately determined.

[0100] In addition, the use of "and" and "or" logic can make the judgment more rigorous and closer to the actual situation. For example, when determining that the fuel is not sufficiently combusted, it can be determined only when the tail gas temperature is less than or equal to the preset temperature or the content of combustion by-products is greater than the preset content. Further, various abnormal conditions that can cause insufficient combustion can be captured in time. In addition, by limiting the tail gas temperature to be greater than the preset temperature and the content of combustion by-products to be less than or equal to the preset content (i.e., only when all indicators meet the sufficient combustion characteristics), the accuracy of determining the actual situation of fuel combustion can be greatly improved.

[0101] In an embodiment, the above-mentioned preset value can be set according to the actual situation, which is not limited. For example, the above-mentioned preset value can be 1. Alternatively, since it can be determined that insufficient combustion of fuel will pollute the rear oxygen sensor, in order to reduce the degree of pollution of the rear oxygen sensor as much as possible to reduce the failure rate, the above-mentioned preset value can also be a value greater than 1.

[0102] Based on the above description, in view of the fact that insufficient fuel combustion increases the risk of contamination of the downstream oxygen sensor, when it is determined that the fuel combustion condition is insufficient fuel combustion, the purpose of increasing the number of starts and stops by the preset value is to: in this way, the number of starts and stops counted can more accurately reflect the actual start and stop conditions of the engine, making it closer to the number corresponding to the frequent start and stop condition of the engine. That is, compared to the number of starts and stops counted purely from the frequency of starting and stopping, the operation of increasing the number of starts and stops by the preset value based on insufficient fuel combustion can more comprehensively consider the factor of fuel combustion condition when subsequently determining whether the engine is in a frequent start and stop condition. Further, the operation of more accurately determining whether to switch the heating voltage control strategy of the downstream oxygen sensor in the subsequent steps can be performed to ensure that the downstream oxygen sensor can still operate normally under complex and potentially contaminated conditions.

[0103] Based on the above examples, it can be understood that even if the actual number of engine starts and stops in the current driving cycle is greater than the above-mentioned preset number, since the fuel is fully combusted each time the engine starts and stops, the hybrid vehicle will not determine that the start and stop condition is a frequent start and stop condition. Based on this, the hybrid vehicle can avoid prematurely adjusting the heating voltage of the downstream oxygen sensor using the second strategy. Further, on the basis of ensuring the normal operation of the downstream oxygen sensor, the energy consumption required for the operation of the downstream oxygen sensor is reduced.

[0104] Based on the above examples, it can be understood that even if the actual number of engine starts and stops in the current driving cycle is greater than the above-mentioned preset number, since the fuel is fully combusted each time the engine starts and stops, the hybrid vehicle will not determine that the start and stop condition is a frequent start and stop condition. Based on this, the hybrid vehicle can avoid prematurely adjusting the heating voltage of the downstream oxygen sensor using the second strategy. Further, on the basis of ensuring the normal operation of the downstream oxygen sensor, the energy consumption required for the operation of the downstream oxygen sensor is reduced.

[0105] S103、In the case of a frequent start and stop condition, the heating voltage control strategy of the downstream oxygen sensor is switched from the first strategy to the second strategy.

[0106] In the case of a frequent start and stop condition, the heating voltage control strategy of the downstream oxygen sensor is switched from the first strategy to the second strategy.

[0107] In an embodiment, the above-mentioned conditions can be considered to describe the working scenario of the downstream oxygen sensor, which can be characterized by a preset parameter. Illustratively, the above-mentioned preset parameters include but are not limited to the flow rate through the downstream oxygen sensor, the exhaust gas temperature, etc., without limitation. That is, the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same conditions (e.g., under the same flow rate and exhaust gas temperature).

[0108] In an embodiment, the first strategy can be considered as a strategy corresponding to a normal start-stop condition. In the normal start-stop condition, the fuel of the engine is fully combusted, and there is no pollution to the downstream oxygen sensor or the pollution to the downstream oxygen sensor is less.

[0109] Based on this, it can be considered that the downstream oxygen sensor can work normally in the normal start-stop condition. Therefore, in order to save energy consumption, the hybrid vehicle can determine and adjust the heating voltage based on the first strategy.

[0110] However, in the frequent start-stop condition, based on the above explanation of the frequent start-stop condition, it can be considered that the downstream oxygen sensor is heavily polluted in this condition. Moreover, the downstream oxygen sensor can decompose and volatilize the exhaust oil attached to the surface at high temperature, reduce the attachment and accumulation of the oil, stabilize the performance of the internal sensor element, and make the downstream oxygen sensor recover the function at high temperature.

[0111] Based on this, switching the heating voltage control strategy of the downstream oxygen sensor from the first strategy to the second strategy can make the heating voltage determined from the second strategy at least equal to the heating voltage determined from the first strategy under the same conditions, so as to enable the downstream oxygen sensor to recover the function at high temperature and reduce the failure rate of the high-temperature sensor. Moreover, determining the heating voltage based on the second strategy can also make the determined heating voltage more reasonable than the subjectively set heating voltage. Furthermore, on the basis of ensuring that the downstream oxygen sensor can recover the function at high temperature, energy saving is maximized.

[0112] Among them, the first strategy and the second strategy can be set in advance, and are not limited. For example, it can be considered that the first strategy and the second strategy can be used to describe the corresponding relationship between the exhaust gas temperature at the downstream oxygen sensor and the heating voltage. Moreover, the corresponding relationship can include an inverse relationship between the exhaust gas temperature and the heating voltage.

[0113] It can be understood that the greater the exhaust gas temperature, the more it can be considered that the fuel combustion condition of the engine during operation is generally closer to the condition of full combustion of the fuel. At this time, the pollution degree of the oil to the downstream oxygen sensor is generally low, and therefore, a large heating voltage can not be required to increase the temperature of the downstream oxygen sensor. Based on this, the corresponding heating voltage can be smaller when the exhaust gas temperature is greater, until the downstream oxygen sensor does not need to be heated. That is, until the heating voltage is 0.

[0114] As a specific example, the first strategy can be as shown in Table 1 below, and the second strategy can be as shown in Table 2 below. Details are as follows:

[0115] Table 1:

[0116]

[0117] Table 2:

[0118]

[0119] Based on the above Table 1 and Table 2, it can be known that, before 800 degrees Celsius, the heating voltage determined from Table 2 is greater than the heating voltage determined from Table 1 under the same working scenario (the same exhaust gas temperature). And in Table 1 and Table 2, the higher the exhaust gas temperature is, the lower the heating voltage is, until the heating voltage is 0.

[0120] However, when the exhaust gas temperature is greater than or equal to 800 degrees Celsius, it can be considered that the temperature in the cylinder of the engine is already high. At this time, the heating voltage determined from Table 1 and Table 2 can be the same, until the post-oxygen sensor does not need to be heated based on the heating voltage.

[0121] In another embodiment, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature under the same exhaust gas temperature. That is, the greater the exhaust gas temperature is, the smaller the voltage difference between the heating voltage determined from Table 2 and the heating voltage determined from Table 1 under the same exhaust gas temperature will be, until both are 0.

[0122] For example, in Table 2 and Table 1, the corresponding voltage difference is 12.2-11.5=0.7 at 300°C; the corresponding voltage difference is 11.8-11.4=0.4 at 400°C; the corresponding voltage difference is 10.6-10.3=0.3 at 600°C. The corresponding voltage difference is 9-8.8=0.2 at 700°C. And above 700°C, the voltage difference is 0.

[0123] Based on this, when the exhaust gas temperature is low, it can be considered that the pollution degree of the post-oxygen sensor is heavy, so the voltage difference between the heating voltage determined from the second strategy and the heating voltage determined from the first strategy can be greater. In turn, the surface temperature of the post-oxygen sensor can be raised more quickly, and the attachment and accumulation of oil stains can be prevented more effectively.

[0124] However, when the exhaust gas temperature is high, it can be considered that the pollution degree of the post-oxygen sensor is small, so on the basis of ensuring that the oil stains with small pollution degree can be cleaned, the heating voltage determined from the second strategy can be reduced from the heating voltage determined from the first strategy to save energy. That is, when the exhaust gas temperature is high, the heating voltage determined from the second strategy is greater than the heating voltage determined from the first strategy, but the amplitude of the voltage difference between the two can be reduced.

[0125] Based on the above description, by setting the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy and the tail gas temperature in a reverse proportional relationship at the same tail gas temperature, the actual heating demand of the downstream oxygen sensor at different tail gas temperatures can be fully considered, and the energy waste caused by determining a larger heating voltage from the second strategy when the tail gas temperature is high can be avoided. While ensuring the normal operation of the downstream oxygen sensor, reasonable allocation and efficient use of energy are realized.

[0126] In an embodiment, the first strategy and the second strategy corresponding to the above Tables 1 and 2 respectively are only one example. In another embodiment, the hybrid vehicle can also establish the above first strategy and second strategy based on only the flow rate, or based on the flow rate and gas temperature information at the same time. In this embodiment, the specific adjustment mode of the heating voltage in the first strategy and the second strategy is not limited.

[0127] S104, adjusting the heating voltage of the downstream oxygen sensor based on the second strategy.

[0128] In an embodiment, the adjustment mode of the heating voltage based on the second strategy can be as described in the above example, which is not limited. It should be noted that when the start-stop working condition is a normal start-stop working condition, the hybrid vehicle can maintain the first strategy and adjust the heating voltage based on the first strategy.

[0129] It can be understood that at the beginning of each driving cycle, the engine has not started or has not stopped after starting. At this time, the start-stop working condition of the engine will be a normal start-stop working condition. Therefore, it can be considered that at the beginning of each driving cycle, the hybrid vehicle determines the heating voltage based on the first strategy. Then, based on the above S101-S104 steps, it is determined whether to switch the first strategy to the second strategy in the current driving cycle, which is not described in detail.

[0130] Based on the above description, it can be considered that in the last driving cycle, even if the first strategy is switched to the second strategy, at the beginning of the current driving cycle, the hybrid vehicle can reset the heating voltage control strategy to the first strategy. Further, at the beginning of each driving cycle, the heating voltage can be adjusted based on the first strategy to save energy.

[0131] Based on the above description, in the current driving cycle, the engine start-stop information of the hybrid vehicle during driving can be obtained to determine the engine start-stop working condition based on the start-stop information. When the start-stop working condition is the frequent start-stop working condition, it can be considered that the frequent start-stop of the engine can cause the fuel not to be fully combusted, so that the oil stain generated by the incomplete combustion adheres to the rear oxygen sensor, causing pollution to the rear oxygen sensor. Based on this, in order to protect the rear oxygen sensor, the heating voltage control strategy of the rear oxygen sensor can be switched from the first strategy to the second strategy when the start-stop working condition is the frequent start-stop working condition. Wherein, since the heating voltage determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same condition, when the heating voltage of the rear oxygen sensor is adjusted based on the second strategy, the temperature of the rear oxygen sensor when operating based on the heating voltage will be greater than or equal to the temperature when operating based on the heating voltage determined by the first strategy. In turn, the rear oxygen sensor can decompose and volatilize the exhaust gas oil stain adhering to the surface based on the higher heating temperature, stabilize the performance of the internal sensor element, and enable the rear oxygen sensor to recover its function at high temperature, thereby reducing the failure rate of the rear oxygen sensor. Moreover, the heating voltage determined based on the second strategy can also be more reasonable than the heating voltage set subjectively. In turn, on the basis of ensuring that the rear oxygen sensor can recover its function at high temperature, energy saving is maximized.

[0132] In order to more clearly illustrate the scheme in the present application, the scheme in the present application will be described below using specific embodiments. For details, please refer to Figure 2 , Figure 2 is an implementation flowchart of a control method of a rear oxygen sensor provided by another embodiment of the present application.

[0133] In the current driving cycle, the hybrid vehicle can obtain the start-stop information of the engine. For example, taking the number of start-stops of the engine as an example. Then, the vehicle can determine the start-stop working condition of the engine based on the start-stop information. For example, when the number of start-stops is greater than a preset number, the start-stop working condition is determined to be the frequent start-stop working condition. Otherwise, when the number of start-stops is less than or equal to the preset number, the start-stop working condition is determined to be the normal start-stop working condition.

[0134] Finally, when the start-stop working condition is the frequent start-stop working condition, the heating voltage control strategy of the rear oxygen sensor is switched from the first strategy to the second strategy. That is, the heating voltage of the rear oxygen sensor is adjusted based on the second strategy. Otherwise, when the start-stop working condition is the normal start-stop working condition, the heating voltage of the rear oxygen sensor is still adjusted based on the first strategy.

[0135] Please refer to Figure 3 , Figure 3 is a structural block diagram of a control device of a rear oxygen sensor provided by an embodiment of the present application. In the present embodiment, each module included in the control device of the rear oxygen sensor is used to execute Figures 1 to 2The steps in the corresponding embodiments. Please refer to Figures 1 to 2 and Figures 1 to 2 The relevant description in the corresponding embodiments. For ease of illustration, only the part related to the present embodiment is shown. Please refer to Figure 3 , the control device 300 of the rear oxygen sensor can include an acquisition module 310, a determination module 320, a switching module 330, and an adjustment module 340, wherein:

[0136] The acquisition module 310 is configured to acquire start-stop information of the engine when the hybrid vehicle is running in the current driving cycle.

[0137] The determination module 320 is configured to determine a start-stop working condition of the engine based on the start-stop information.

[0138] The switching module 330 is configured to switch the heating voltage control strategy of the rear oxygen sensor from the first strategy to the second strategy when the start-stop working condition is a frequent start-stop working condition; the heating voltage of the rear oxygen sensor determined from the second strategy is greater than or equal to the heating voltage determined from the first strategy under the same working scenario.

[0139] The adjustment module 340 is configured to adjust the heating voltage of the rear oxygen sensor based on the second strategy.

[0140] In an embodiment, the start-stop information includes a start-stop frequency, and the acquisition module 310 is further configured to:

[0141] acquire exhaust information at the rear oxygen sensor when the engine is switched from a starting state to a stopping state; and determine the start-stop frequency based on the exhaust information.

[0142] In an embodiment, the acquisition module 310 is further configured to:

[0143] determine a fuel combustion condition of the engine based on the exhaust information; if the fuel combustion condition is full fuel combustion, maintain the start-stop frequency unchanged; if the fuel combustion condition is insufficient fuel combustion, add the current start-stop frequency and a preset value to obtain an updated start-stop frequency.

[0144] In an embodiment, the exhaust information at least includes one of an exhaust temperature and a content of combustion byproducts; in an embodiment, the acquisition module 310 is further configured to:

[0145] if the exhaust temperature is less than or equal to a preset temperature, and / or, the content of combustion byproducts is greater than a preset content, determine that the fuel combustion condition is insufficient fuel combustion;

[0146] if the exhaust temperature is greater than the preset temperature, and the content of combustion byproducts is less than or equal to the preset content, determine that the fuel combustion condition is full fuel combustion.

[0147] In an embodiment, the start-stop information comprises a start-stop number, and the determining module 320 is further configured to:

[0148] If the start-stop number is greater than a preset number, the start-stop condition is determined as a frequent start-stop condition; if the start-stop number is less than or equal to the preset number, the start-stop condition is determined as a normal start-stop condition.

[0149] In an embodiment, the start-stop information comprises an interval duration between each start and stop of the engine; and the determining module 320 is further configured to:

[0150] determine an average duration of the multiple interval durations; if the average duration is less than or equal to a preset duration, the start-stop condition is determined as a frequent start-stop condition; if the average duration is greater than the preset duration, the start-stop condition is determined as a normal start-stop condition.

[0151] In an embodiment, the control device 300 of the rear oxygen sensor further comprises:

[0152] The executing module is configured to, at a start stage of each driving cycle, determine the heating voltage based on the first strategy, and execute the target step and the steps after the target step; the target step comprises obtaining start-stop information of the engine when the hybrid vehicle is running.

[0153] In an embodiment, the first strategy and the second strategy are respectively used to describe a corresponding relationship between the exhaust gas temperature at the rear oxygen sensor and the heating voltage; wherein, at the same exhaust gas temperature, a voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature.

[0154] It is understood that, Figure 3 In the structural block diagram of the control device of the rear oxygen sensor shown, each module is configured to execute Figures 1 to 2 the steps in the corresponding embodiments, and for the steps in the corresponding embodiments, Figures 1 to 2 have been explained in detail in the above embodiments, please refer to Figures 1 to 2 and Figures 1 to 2 the related descriptions in the corresponding embodiments, which will not be repeated here.

[0155] Figure 4 is a structural block diagram of a vehicle provided in an embodiment of the present application. As Figure 4 shown, the vehicle 400 of this embodiment comprises a processor 410, a memory 420, and a computer program 430 stored in the memory 420 and executable by the processor 410, such as a program of a control method of a rear oxygen sensor. The processor 410 implements the steps in each of the above embodiments of the control method of the rear oxygen sensor when executing the computer program 430, such as Figure 1 S101-S104 shown. Alternatively, the processor 410 implements the steps in each of the above embodiments of the control method of the rear oxygen sensor when executing the computer program 430.Figure 3 corresponding embodiments, for example, Figure 3 corresponding embodiments, for example, Figure 3 corresponding embodiments, for example.

[0156] For example, the computer program 430 can be divided into one or more modules, one or more modules are stored in the memory 420 and executed by the processor 410 to implement the control method of the rear oxygen sensor provided by the embodiments of the present application. One or more modules can be a series of computer program instruction segments capable of completing a specific function, which is used to describe the execution process of the computer program 430 in the vehicle 400. For example, the computer program 430 can implement the control method of the rear oxygen sensor provided by the embodiments of the present application.

[0157] The vehicle 400 can include, but is not limited to, the processor 410, the memory 420. Those skilled in the art can understand that, Figure 4 The vehicle 400 is only an example and does not constitute a limitation on the vehicle 400, and can include more or fewer components than shown, or combine certain components, or different components, for example, the vehicle can also include an input / output device, a network access device, a bus, etc.

[0158] The processor 410 can be a central processing unit, and can also be other general-purpose processors, digital signal processors, application-specific integrated circuits, ready programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0159] The memory 420 can be an internal storage unit of the vehicle 400, for example, a hard disk or a memory of the vehicle 400. The memory 420 can also be an external storage device of the vehicle 400, for example, a plug-in hard disk, a smart memory card, a flash memory card, etc. equipped on the vehicle 400. Further, the memory 420 can include both the internal storage unit and the external storage device of the vehicle 400.

[0160] The embodiments of the present application provide a computer readable storage medium, including a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the control method of the rear oxygen sensor in each of the above embodiments.

[0161] The embodiments of the present application provide a computer program product, when the computer program product is executed on the vehicle, so that the vehicle executes the control method of the rear oxygen sensor in each of the above embodiments.

[0162] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A control method of an exhaust gas oxygen sensor, characterized by, The method comprises: In the current driving cycle, obtaining engine start-stop information when the hybrid vehicle is running; Determine the start-stop condition of the engine based on the start-stop information; When the start-stop condition is a frequent start-stop condition, switch the heating voltage control strategy of the rear oxygen sensor from a first strategy to a second strategy; the rear oxygen sensor determines a heating voltage from the second strategy that is greater than or equal to a heating voltage determined from the first strategy under the same working scenario; Adjust the heating voltage of the rear oxygen sensor based on the second strategy; the first strategy and the second strategy each describe a corresponding relationship between the exhaust gas temperature and the heating voltage at the rear oxygen sensor; wherein, under the same exhaust gas temperature, the voltage difference between the heating voltage corresponding to the second strategy and the heating voltage corresponding to the first strategy is inversely proportional to the exhaust gas temperature; the same working scenario is the scenario of the same exhaust gas temperature.

2. The method of claim 1, wherein, The start-stop information includes the number of start-stops; the method of obtaining engine start-stop information when the hybrid vehicle is running comprises: When the engine switches from a start state to a stop state, obtain the exhaust information at the rear oxygen sensor; Determine the number of start-stops based on the exhaust information.

3. The method of claim 2, wherein, The method of determining the number of start-stops based on the exhaust information comprises: Determine the fuel combustion condition of the engine based on the exhaust information; If the fuel combustion condition is full fuel combustion, maintain the number of start-stops unchanged; If the fuel combustion condition is insufficient fuel combustion, add the current number of start-stops to a preset value to obtain an updated number of start-stops.

4. The method of claim 3, wherein, The exhaust information includes at least one of the exhaust temperature and the content of combustion byproducts; the method of determining the fuel combustion condition of the engine based on the exhaust information comprises: If the exhaust temperature is less than or equal to a preset temperature, and / or the content of combustion byproducts is greater than a preset content, it is determined that the fuel combustion condition is insufficient fuel combustion; If the exhaust temperature is greater than the preset temperature and the content of combustion byproducts is less than or equal to the preset content, it is determined that the fuel combustion condition is full fuel combustion.

5. The method according to any one of claims 1 to 4, characterized in that, The start-stop information includes the number of start-stops; the method of determining the start-stop condition of the engine based on the start-stop information comprises: If the number of start-stops is greater than a preset number, it is determined that the start-stop condition is a frequent start-stop condition; If the number of start-stops is less than or equal to the preset number, it is determined that the start-stop condition is a normal start-stop condition.

6. The method of claim 1, wherein, The start-stop information includes the interval duration between each start and stop of the engine; The method of determining the start-stop condition of the engine based on the start-stop information further comprises: Determine the average duration of multiple interval durations; If the average duration is less than or equal to a preset duration, it is determined that the start-stop condition is a frequent start-stop condition; If the average duration is greater than the preset duration, it is determined that the start-stop condition is a normal start-stop condition.

7. The method according to any of claims 1 to 4 or 6, characterized in that, The method further comprises: At a beginning stage of each driving cycle, the heating voltage is determined based on the first strategy, and a target step and steps after the target step are performed; the target step includes obtaining engine start-stop information when the hybrid vehicle is running.

8. A vehicle characterized by comprising: A computer program product comprising a processor, a memory, and a computer program stored in the memory and loadable on the processor, characterized in that the processor executes the computer program so that the vehicle implements the method according to any one of claims 1-7.

9. A computer program product, characterised in that, A computer program product comprising a computer program which, when executed, causes the method according to any one of claims 1-7 to be performed.

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